The present invention relates in general to a flotation device for measuring the level of a liquid, and more specifically to means for interconnecting a float and a float rod.
Fuel level sensing in automobile fuel tanks is typically accomplished using a pivotable float which controls movement of a wiper contact over a resistor. Electrical connections to the wiper contact and to the resistor result in a variable measure of resistance as the float moves in accordance with the level of fuel in the tank. A signal resulting from the variable resistance is sent to an indicator, such as an electronic gauge, to indicate to a vehicle operator the amount of fuel present in the tank.
The variable resistor mechanism and the float body are typically interconnected by a steel float rod arm extending therebetween. Various techniques are known for connecting the float to the float rod.
For example, U.S. Pat. No. 2,325,582 issued to Anderson and U.S. Pat. No. 3,316,763 issued to De Giers, show a float rod arm terminating in a U-shaped bracket which carries a shaft. A float member is rotatably retained on the shaft. By means of the rotation of the float body, the body maintains a horizontal orientation at the surface of the liquid being measured. This type of float and float arm assembly is undesirable due to the expense and complexity required to manufacture and assemble the large number of parts involved.
U.S. Pat. No. 3,361,156 issued to Klingle, discloses a float body secured to a valve arm by means of barbs projecting from the valve arm and penetrating the float body. In large volume production, the low weight and cost of a thin steel float rod are preferred to the large bracket which is required in Klingle. Furthermore, barbs cannot easily penetrate into plastic float bodies which are typically used in fuel tanks for their imperviousness to combustion fuels.
Donko et al., U.S. Pat. No. 3,200,646, discloses what is known as a shepherd's hook attachment between a float body and a float rod. A cylindrical float body includes a groove for receiving the arcuately bent end portion of a float rod. The shepherd's hook design is lacking in durability and does not provide retention of the float body equally strongly against forces applied to the float body in all directions. It is also possible that the float body could be assembled in the shepherd's hook oriented in the wrong direction.
These are some of the disadvantages that the present invention overcomes.